In previous meta-analyses, it has been shown that patient education and psychosocial support (hereafter called psychoeducational care) is beneficial for adult surgical patients. These interventions were associated with improved recovery, psychological well-being, and satisfaction with care, as well as with reduced postsurgical pain. The proposed, two-phase project is an extension of this program of research. The main aim in Phase 1 is to make this largely unpublished, yet methodologically strong body of research more accessible to clinicians, researchers, and theoreticians (a) by describing which of the many types of psychoeducational care have been tested with which outcomes, and (b) by using between and within-study contrasts to probe which are the more effective types of psychoeducational care. Phase 2 will be used to extend this research to adults with chronic disease. The specific aims are to determine (a) what the effects of psychoeducational care are on patient knowledge, compliance, and well-being among adults with chronic disease; (b) if selected threats to the internal or construct validity of the meta-analysis are plausible; (c) the extent to which the effects are generalizable; and (d) whether some types of psychoeducational care are more effective than others in increasing knowledge, compliance, or patient well-being among adults with chronic disease. Meta-analysis of existing experimental and quasi-experimental research will be the methodology. It is estimated that at least 135 studies will be analyzed in Phase 1 and 125 studies in Phase 2. This project will contribute to nursing and health care in many ways. First, reviews are more convincing than single studies, because any individual study, no matter how good the design and measurement, may achieve statistical significance strictly by chance. As such, this extensive, quantitative review should yield clinically and policy relevant knowledge from which to plan research-based psychoeducational care for two prevalent patient groups. Second, this knowledge should be useful for future research and middle-range theory generation. Third, data will be provided from which to address issues in the meta-analysis of nursing research.